JP5309019B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator that is mounted on a vehicle such as an automobile or an industrial machine.

This type of vibration isolator is used by being mounted on a vehicle in which a drive unit having an engine is provided on the body frame. Conventionally, vibration generated by the drive unit is suppressed from being transmitted to the body frame, for example, good. Various proposals have been made to provide excellent ride comfort and handling stability (see, for example, Patent Document 1).
JP-A-11-325165

  In recent years, there is an increasing demand for further improving steering stability. Therefore, as a result of intensive investigations to cope with such demands, the inventors have found that this drive unit is caused by the vibration behavior of the drive unit regardless of whether the vehicle is traveling straight or turning. As a result, the torque transmitted to the tire via the drive shaft etc. fluctuates due to the vibration of the vehicle, and this causes the propulsive force etc. generated between the tire ground contact surface and the ground to fluctuate, which deteriorates the steering stability. It has been found that

  The present invention has been made in consideration of such circumstances, and an object thereof is to provide a vibration isolator capable of further improving the steering stability.

In order to solve the above problems and achieve such an object, the vibration isolator of the present invention is a vibration isolator in which a drive unit having a transverse engine is provided in a vehicle body frame. A connecting member for connecting the frame, a detecting means for detecting an acceleration in the roll rotation direction with respect to the ground surface of the drive unit, and the connecting member is operated based on a detection signal from the detecting means to vibrate the drive unit. A control unit that controls at least roll vibration of the drive unit among the behaviors is provided.

  According to this invention, since the connecting member is operated based on the detection signal from the detection means and the control unit for controlling at least the roll vibration of the drive unit among the vibration behavior of the drive unit is provided, the drive unit It is possible to suppress fluctuations in the torque transmitted from the drive unit to the drive shaft due to the vibration behavior of itself, and the torque transmitted to the tire can be stabilized. Therefore, for example, it is possible to suppress fluctuations in the propulsive force generated between the tire ground contact surface and the ground, and the steering stability can be improved.

In the present invention, the detecting means, from the drive unit may be configured to detect the variation of torque tire axial ends is transmitted to the drive shaft that will be connected, according to this, it is transmitted to the tires Torque fluctuation can be detected more accurately.

  Further, the connecting member is preferably a mount member or a torque rod that elastically connects the drive unit and the vehicle body frame, so that transmission of vibration of the drive unit to the vehicle body frame can be suppressed. Thus, it is possible to achieve good riding comfort and to easily control the vibration behavior of the drive unit by operating this connecting member.

  Further, the connecting member may be provided on both sides of the drive unit with the crankshaft sandwiched in the horizontal direction. In this case, since the connecting members are respectively provided on both sides of the drive unit with the crankshaft sandwiched in the horizontal direction, the roll vibration is easily and reliably suppressed by operating the connecting members as described above. be able to.

Further, the detection means may be provided on at least one of an outer surface of a case and a crankshaft constituting the outer shell of the drive unit. In this case, when the detecting means is provided on the outer surface of the case constituting the outer shell of the drive unit, for example, a stone on the ground collides with the detecting means or the detecting means is prevented from being exposed to wind and rain. Can do.
Further, if the detecting means is provided on the crankshaft, it is possible to detect the fluctuation of torque transmitted from the drive unit to the drive shaft with high accuracy.

In addition, the control unit may control a frequency component of at least 5 Hz to 50 Hz in the roll vibration of the drive unit, and in this case, the above-described effects can be reliably achieved.

It is a schematic block diagram which shows the state with which the vibration isolator shown as embodiment which concerns on this invention was mounted | worn with the vehicle. It is a mimetic diagram showing plane arrangement of an engine concerning an embodiment of the present invention. It is a schematic side view of the corresponding engine to A-A arrow in FIG. It is a block diagram which shows the control structure of the vibration isolator of embodiment of this invention. It is a block diagram showing a system used when designing a feedback matrix. It is a graph which shows the frequency dependence of the amplitude of the displacement of the point where the acceleration sensor is fixed.

Explanation of symbols

2 Body frame 3a, 3b ACM
4a, 4b Acceleration sensor 10 Vibration isolator 11 Drive unit 11a Engine 11b Transmission 11c Crankshaft 12 Driveshaft 13 Tire 14 Vehicle 16 Connecting member 17 Detection means 18 Control unit 18a First amplifier 18b Filter 18c High-speed arithmetic unit 18e Second amplifier O Roll axis

  Hereinafter, an embodiment of a vibration isolator according to the present invention will be described with reference to FIG. This vibration isolator 10 is a vehicle in which a body unit 2 is provided with a drive unit 11 having an engine 11a, and a drive shaft 12 to which torque is transmitted from the engine 11a and tires 13 are connected to both ends in the axial direction. 14 includes a connecting member 16 used to connect the drive unit 11 and the vehicle body frame 2 to each other.

The drive unit 11 is provided on the front side of the vehicle 14 inside the body frame 2, and includes an engine 11a, a transmission 11b, a crankshaft 11c, and the like. The crankshaft 11 c extends along the left-right direction of the vehicle 14.
The drive shaft 12 extends along the left-right direction of the vehicle 14 at a position away from the crankshaft 11 c in the front-rear direction of the vehicle 14. In the illustrated example, the drive shaft 12 is provided on the rear side of the vehicle 14 with respect to the crankshaft 11c. The torque of the crankshaft 11c is transmitted to the drive shaft 12 via the transmission 11b.
A pair of left and right tires 13 provided on the front side of the vehicle 14 are respectively connected to both ends of the drive shaft 12 and rotate as the drive shaft 12 is rotated about its axis. ing.

Here, the vibration behavior of the drive unit 11 itself mainly includes the vertical vibration of the vehicle 14, the horizontal vibration, the front-rear vibration, and the roll vibration around the roll axis O of the drive unit 11. Vibration causes the torque transmitted from the drive unit 11 to the drive shaft 12 to vary most greatly in the vehicle 14 of the present embodiment.
Note that the roll axis O is a virtual axis determined from the moment of inertia of the drive unit 11 due to the performance and arrangement position of the connecting member 16, and is located between the crankshaft 11c and the drive shaft 12. Yes.
In the present embodiment, the vibration isolator 10 includes a detection unit 17 that detects vibration with respect to the ground plane of the drive unit 11, and the connection member 16 is operated based on a detection signal from the detection unit 17, thereby driving the drive unit. 11 and a control unit 18 for controlling the roll vibration (for example, 5 Hz to 50 Hz).

  The detection means 17 is an acceleration sensor in the illustrated example, and is attached to the outer surface of the case of the engine 11a in the case constituting the outline of the drive unit 11, and measures the acceleration of the drive unit 11 in the longitudinal direction of the vehicle. Thus, it is possible to detect a variation in torque transmitted from the drive unit 11 to the drive shaft 12. In addition, the detection means 17 is attached to the upper end part in the case outer surface of the engine 11a.

The connecting member 16 is a mount member that elastically supports the drive unit 11 from below. Further, in the present embodiment, the connecting members 16 are respectively provided on both sides of the drive unit 11 sandwiching the crankshaft 11c from the direction orthogonal to the extending direction in the horizontal direction. In the illustrated example, each connecting member 16 is connected to both sides of the drive unit 11 in the front-rear direction of the vehicle 14 and is provided as a pair. One connecting member 16 is disposed on the front side of the vehicle 14 with respect to the crankshaft 11c. In addition, the other connecting member 16 is disposed on the rear side of the vehicle 14 with respect to the roll axis O.
Each connecting member 16 is connected to, for example, a fluid pressure cylinder so as to be movable up and down in the vehicle 14.

  The control unit 18 amplifies the detection signal from the detection means 17 and a specific frequency band correlated with the roll vibration of the drive unit 11 from the detection signal processed by the first amplifier 18a. A filter 18b that removes other frequency components (for example, an acceleration component during acceleration / deceleration of the vehicle itself) and controls the two connecting members 16 described above based on the detection signal processed by the filter 18b. A high-speed arithmetic device 18c that determines the target connecting member 16 and determines the control amount thereof, and a second amplifier 18e that amplifies the data of the control amount are provided.

And based on the calculation result in this control part 18, by operating a pair of connecting member 16 separately, the said roll vibration of the drive unit 11 is suppressed.
That is, in FIG. 1, for example, when the drive unit 11 rotates clockwise with respect to the roll axis O, the connection member 16 disposed on the rear side of the vehicle 14 among the pair of connection members 16 is driven. In the unit 11, a driving force that pushes the rear side of the vehicle 14 upward is applied, while the connecting member 16 disposed on the front side of the vehicle 14 is connected to the front side of the vehicle 14 in the drive unit 11. A connecting member disposed on the front side of the vehicle 14 among the pair of connecting members 16 when a driving force is applied to pull downward and the drive unit 11 rotates counterclockwise with respect to the roll axis O. 16 is applied with a driving force that pushes the front side of the vehicle 14 upward in the drive unit 11, while the connecting member 16 disposed on the rear side of the vehicle 14 has a drive unit 11. Imparting driving force that pulls the side of the side after the Oite vehicle 14 downward.

  As described above, according to the vibration isolator 10 according to the present embodiment, the control unit 18 that operates the connecting member 16 based on the detection signal from the detection unit 17 and controls the roll vibration of the drive unit 11 is provided. Therefore, the torque transmitted from the drive unit 11 to the drive shaft 12 due to the vibration behavior of the drive unit 11 itself can be suppressed, and the torque transmitted to the tire 13 can be reduced. It can be stabilized. Accordingly, for example, it is possible to suppress fluctuations in the propulsive force generated between the ground contact surface of the tire 13 and the ground, and the steering stability can be improved.

  In the present embodiment, since the connecting member 16 is a mount member that elastically connects the drive unit 11 and the vehicle body frame 2, it is possible to suppress the vibration of the drive unit 11 from being transmitted to the vehicle body frame 2. Thus, it is possible to provide a good riding comfort and to easily control the vibration behavior of the drive unit 11 by operating the connecting member 16.

Furthermore, in this embodiment, since the connecting member 16 is provided on both sides of the drive unit 11 with the crankshaft 11c sandwiched in the horizontal direction, by operating the connecting member 16 as described above, the roll Vibration can be easily and reliably suppressed.
Furthermore, since the detection means 17 is provided on the outer surface of the case that constitutes the outline of the drive unit 11, for example, a stone on the ground collides with the detection means 17, or the detection means 17 is exposed to wind and rain. Can be prevented.

With respect to this embodiment, a control method that can more effectively control roll vibration and improve steering stability will be exemplified below. Figure 2 is a schematic view showing a planar arrangement of the engine 11a realizing this control method, Figure 3 is a schematic side view of the engine corresponding to the A-A arrow in FIG. 2, the engine 11a is The body frame 2 is supported by a plurality of (two in the illustrated example) ACMs 3a and 3b constituting the connecting member 16. These ACM3a, 3b serves to prevent the both when supporting the engine, the vibration damping force in addition to actively engine 11a is transmitted to the vehicle body.

  Further, the acceleration sensor 4a, 4b constituting the detecting means 17 is fixed to the engine 11a at a plurality of locations (two locations in the figure) on the surface (in the illustrated case, the upper surface of the engine). It functions to detect the acceleration at those points in real time. These acceleration sensors 4a and 4b are set so as to detect the rotational component around the roll axis O, that is, the acceleration in the roll rotation direction of the engine 11a (the longitudinal direction of the vehicle).

  FIG. 4 is a block diagram showing the control configuration of the vibration damping device 10 of this embodiment. The vibration damping device 10 supports the engine 11a with respect to the vehicle body frame 2 and a plurality of ACMs 3a for damping the same. 3b, a plurality of acceleration sensors 4a and 4b fixed at different positions on the surface of the engine 11a, and the vibration control force of the ACMs 3a and 3b based on acceleration signals from the acceleration sensors 4a and 4b. And a control unit 18.

The control unit 18 has a plurality of predetermined feedback filter matrices and a plurality of acceleration signals α ₁ and α ₂ from the plurality of acceleration sensors 4a and 4b, which vary as the vehicle travels. A high-speed arithmetic device 11c that calculates signals β ₁ and β ₂ for controlling the vibration damping forces of the ACMs 3a and 3b in real time is provided. The control unit 18 is also provided with a first amplifier 18a that amplifies signals from the acceleration sensors 4a and 4b in order to obtain acceleration signals α ₁ and α _2, and outputs an output signal from the high-speed arithmetic device 11c to β _1, ACM3a amplifies the beta _2, first amplifier 18a to be input to 3b is arranged.

  In the present invention, the main purpose is to dampen the roll resonance mode of the engine. In that case, the filter 18b passes only a frequency of 10 to 20 Hz including a resonance frequency of a general engine. Is preferred.

The output signals β ₁ and β ₂ can be obtained by Equation (1) using a feedback filter matrix based on the acceleration signals α ₁ and α ₂ .

Here, A ₁ (s), A ₂ (s), B ₁ (s), and B ₂ (s) are Laplace transforms of α ₁ , α ₂ , β ₁ , and β ₂ , respectively.

Further, K ₁₁ , K ₁₂ , K ₂₁ , and K ₂₂ constituting the feedback filter matrix can be designed as follows, for example. That is, this design is regarded as a mixed sensitivity problem in the H∞ control using the input end disturbance, and in the system shown in FIG. 4, the transfer function W _s from the disturbances w ₁ and w ₂ to the controlled variables z ₁ and z _{2 is obtained.} The H∞ norm of M and the H∞ norm of the transfer function W _t T from the disturbances w ₁ and w ₂ to the controlled variables z ₃ and z ₄ are obtained, and M in these transfer functions W _s M and W _t T, Since T is a function of the controller K, the controller K can be obtained by designing the entire system so as to reduce the H∞ norm of these transfer functions W _s M and W _t T.

Here, in FIG. 4, P is a measured and modeled transfer function of an actual system from the ACM to the acceleration sensor, K is a controller to be designed, and K ₁₁ and K ₁₂ in the equation (1). , K ₂₁ , K ₂₂ , w ₁ , w ₂ are disturbance inputs, w ₃ is observation noise, W _s , W _t , and W _n are weight functions, W _s , The controller K is designed so as to reduce the transfer function while correcting W _t by trial and error. However, when actually controlling the system, this is converted into a state equation and controlled in real time in the time domain.

  The feature of the present invention described above is that an acceleration signal at a plurality of locations is fed back as a signal for controlling the damping force of the ACM. With this, only one acceleration signal is fed back. In this case, it is possible to suppress the vibration only at the point to be controlled, but it is possible to solve the problem that the vibration becomes large at other points.

  In particular, in the present invention, vibration in the roll rotation direction around the roll axis O, which is generated by driving the engine itself, is suppressed. In this case, translational component vibration is likely to occur at other points. However, as described above, the vibration of the translation component can be effectively suppressed by feeding back the acceleration signal at a plurality of locations as the signal for controlling the damping force of the ACM.

  As the position of the acceleration sensors 4a and 4b, when trying to suppress vibration in the roll direction of the engine, it is preferable to select a point on the engine farthest from the roll axis O as the first position. As the second position, it is preferable to select a position where the vibration becomes large when the vibration at the first position is controlled to be minimum, and these are preferably on the same plane.

  In the engine arrangement shown in FIG. 2 and FIG. 3, the frequency of the displacement amplitude at the point where the acceleration sensor 3a is fixed from the acceleration signal detected by the acceleration sensor 3a by exciting the platform on which the vehicle is mounted with a shaker. The dependence was graphed and the results are shown in FIG. In Example 1 shown by the solid line in FIG. 6, the result of controlling the two acceleration signals of the acceleration sensors 3 a and 3 b while feeding back to the two ACMs, Example 2 shown by the broken line The results when control is performed while only the acceleration signal of one acceleration sensor 3a is fed back to two ACMs, and the comparative example indicated by the two-dot chain line show the results when the ACM is not controlled.

  As is clear from FIG. 6, all of the examples show that the vibration can be suppressed extremely effectively in the frequency band of 10 to 15 Hz to be controlled as compared with the comparative example. As a result, steering stability can be greatly improved. In addition, the first embodiment shows an equivalent control result in the frequency band of 10 to 15 Hz to be controlled as compared to the second embodiment, and shows that vibration can be suppressed in a band outside the control target. That is, it shows that the ride comfort can be greatly improved without sacrificing the effect of improving the steering stability by feeding back the acceleration signals at multiple locations as a signal to control the damping force of the ACM. ing.

  The vehicle used for the test was equipped with a 2500cc diesel engine, and as a vibration condition, only the front wheels were placed on the vibration table, and the frequency was continuously increased from 5 to 20 Hz. Then, it was vibrated while continuously decreasing the frequency from 20 to 5 Hz. During this time, the gear was set to the neutral position and only the side brake was applied. An ACM provided with an electromagnetic actuator was used.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, an acceleration sensor is shown as the detection unit 17, and the detection unit 17 is attached to the outer surface of the case that forms the outline of the drive unit 11. Instead, a rotation angle sensor is used, This sensor may be provided on the crankshaft 11c.

  In this case, the fluctuation of the torque transmitted from the drive unit 11 to the drive shaft 12 can be detected by calculating the angular acceleration from the rotation angle data of the crankshaft 11c measured by the rotation angle sensor.

  Furthermore, instead of the detection means 17 of the above-described embodiment, a detection means including a light source that irradiates light on the outer surface of the tire 13 and a photosensor that detects reflected light from the outer surface of the tire 13 may be employed. . In this case, it is possible to detect the variation in torque described above from the difference in light wave amplitude or light wave frequency of the reflected light sensed by the photosensor at a predetermined time interval.

Furthermore, the detection means 17 may be configured to have both the rotation angle sensor and the acceleration sensor shown in FIG.
Furthermore, the acceleration sensor may be attached to the outer surface of the case of the transmission 11b in the case of the drive unit 11.

Moreover, in the said embodiment, although the mount member which can elastically support the self-weight of the drive unit 11 was shown as the connection member 16, it replaced with this, for example, respectively connected with the both ends of this rod. A torque rod that includes first and second cylindrical parts, one cylindrical part is connected to the drive unit 11, and the other cylindrical part is connected to the vehicle body frame may be employed.
Furthermore, in the said embodiment, although the structure which connects the drive unit 11 and the vehicle body frame 2 elastically as the connection member 16 was shown, instead of this, you may employ | adopt actuators, such as a fluid pressure cylinder, for example. .

Further, in the above embodiment, the drive unit 11 is provided on the front side of the vehicle 14 inside the body frame 2, but instead, for example, it may be provided on the rear side of the vehicle 14 inside the body frame 2. Furthermore, the present invention can be applied regardless of whether the vehicle is an FF vehicle or an FR vehicle.
Moreover, in the said embodiment, although the structure which controls the said roll vibration among the vibration behavior of the drive unit 11 by operating the connection member 16 was shown, in addition to this roll vibration, the vibration of the front-back direction of the vehicle 14, or / and The vibration in the vertical direction may also be controlled by operating the connecting member 16 in the same manner as in the above embodiment.

  Furthermore, in the said embodiment, although the structure provided so that raising / lowering of the vehicle 14 was possible was shown as the connection member 16, instead of this, for example, while providing each rubber-like elastic body to each connection member 16, respectively. Based on the calculation result in the control unit 18, a configuration may be used in which the vertical rigidity of the vehicle 14 of each rubber-like elastic body is changed.

  That is, in FIG. 1, for example, when the drive unit 11 rotates clockwise with respect to the roll axis O, the pair of connecting members 16 are operated, and the rubber-like elastic body 14 of each connecting member 16 is vertically moved. By increasing the rigidity of the vehicle 14, the connecting member 16 disposed on the rear side of the vehicle 14 pushes the rear side portion of the vehicle 14 upward in the drive unit 11, and the connecting member 16 disposed on the front side of the vehicle 14. When the drive unit 11 is pulled downward on the front side of the vehicle 14 and when the drive unit 11 is rotated counterclockwise with respect to the roll axis O, the rubber shape of each connecting member 16 is the same as described above. By increasing the rigidity of the elastic body 14 in the vertical direction of the vehicle 14, the vehicle is driven in the drive unit 11 by the connecting member 16 disposed on the front side of the vehicle 14. 14 pushes up the front side above the, and may be pulled to the side of the rear side of the vehicle 14 below the drive unit 11 by a coupling member 16 disposed on the rear side of the vehicle 14.

Furthermore, as the connecting member 16, at least the outer cylinder, an attachment member disposed on one end side in the axial direction of the outer cylinder, the attachment member and the outer cylinder are elastically connected, and the shaft of the outer cylinder is provided. A rubber elastic portion that closes the opening at one end in the direction may be provided, and a configuration in which liquid is sealed inside the outer cylinder may be employed.
Then, by controlling the hydraulic pressure in the outer cylinder based on the calculation result in the control unit 18, the vibration of the drive unit 11 is suppressed, and the fluctuation of the torque transmitted from the drive unit 11 to the drive shaft 12 is suppressed. You may do it.
Further, the frequency component of the roll vibration controlled by the control unit 18 is not limited to that of the embodiment.

Claims (6)

In the vibration isolator provided with a drive unit having a horizontally mounted engine on the body frame,
A connecting member for connecting the drive unit and the body frame;
Detecting means for detecting an acceleration in a roll rotating direction with respect to the ground surface of the drive unit;
A vibration isolating apparatus comprising: a control unit that operates the connecting member based on a detection signal from the detection unit and controls at least roll vibration of the drive unit among vibration behaviors of the drive unit. apparatus. It said sensing means, antivibration device according to claim 1, from the driving unit, and detecting a variation in torque tire axial ends is transmitted to the drive shaft that will be connected. The connecting member, serial mounting of the anti-vibration device according to claim 1 or 2, characterized in that the said drive unit and the body frame is mounted member or torque rod for elastically connecting.   The vibration isolator according to any one of claims 1 to 3, wherein the connecting member is provided on each side of the drive unit with a crankshaft sandwiched in the horizontal direction.   5. The vibration isolator according to claim 1, wherein the detection unit is provided on at least one of an outer surface of a case and a crankshaft constituting the outer shell of the drive unit.   6. The vibration isolator according to claim 1, wherein the control unit controls a frequency component of at least 5 Hz to 50 Hz in the roll vibration of the drive unit.

Images